An arena that was barely one-quarter full early in the year was jam-packed and rocking with noise Sunday — and for good reason.

With the Gophers women’s hockey team looking to complete an undefeated season with an NCAA championship, a sellout crowd at Ridder Arena watched Amanda Kessel tally two goals and two assists, giving Minnesota a 6-3 triumph over Boston University and a 41-0 season.

Gophers co-captains Megan Bozek and Bethany Brausen doused Coach Brad Frost with a water cooler, and he spent the rest of the awards ceremony soaking up the arena’s atmosphere.

“I just kept saying to our staff, ‘Look around. I mean, just look around,’ ” Frost said. “There wasn’t an empty seat in the place. I think what this team has done for women’s hockey here at the U, and girls’ hockey in Minnesota, has been huge.”

Bandwagon? You betcha. But Frost said he hopes all the newcomers “are Gophers fans for life.”

Boston University coach Brian Durocher is convinced there were at least a few new college hockey fans in the crowd.

“I was chatting with a couple of 8-year-olds coming off the ice at the end there, and I’m pretty sure they are coming back because that was a great show,” Durocher said.

The Gophers became the first Division I hockey team — men’s or women’s — to complete an undefeated NCAA championship season since the Cornell men’s team went 29-0 in 1970.

“I thought it was impossible,” Kessel said. “But we made the impossible possible.”

Last year, the Gophers won their final eight games to win their third NCAA title. Their winning streak now stands at 49 games.

“It’s very surreal,” Frost said. “I still remember on Day One, I made a comment such as, ‘We’re going to lose a hockey game, so it’s not always about the wins and losses; let’s focus on the process.’

“And here we are, 41 games later without a loss. It’s just mind-boggling. This is an incredibly special team and one that will go down in the history books as one of the best ever, if not the best ever.”

Fans took notice. Scalpers outside Ridder Arena were getting $65 apiece for general admission tickets Sunday — 10 times face value. Not bad, considering the Gophers averaged just 933 fans at their 3,400 seat arena for this season’s first eight home games.

They saw what might be considered the best team ever in women’s hockey history. Frost might hesitate to say it, but after winning Frozen Four MVP honors for the second straight year, senior goaltender Noora Raty didn’t.

“It doesn’t matter how you say it; no other team has done this,” Raty said. “So our record speaks to the fact that it is the best season in women’s hockey history.”

Frost acknowledged that the pressure of finishing a perfect season had started to wear on his team. The Gophers needed three overtimes to get past North Dakota in the NCAA quarterfinals, and another overtime to defeat Boston College on Friday night in the semifinals.

But the championship game never seemed in doubt.

Boston University (28-6-3) trailed just 2-1 after the first period, but the Gophers pulled away with impressive second-period goals by Kessel and Milica McMillen.

Those two goals made it clear that women’s hockey players know the art of the one-timer — a shot taken right off a pass, without stopping the puck. Kessel took a pass from Maryanne Menefee and lifted a laser beam right into the net’s upper-left corner.

Then, with 12 seconds remaining in the second period, Menefee slid another perfect pass to McMillen, who rocketed a slapshot into the twine. The Gophers stayed ahead by at least two goals for the rest of the game.

“I can’t stop smiling,” Kessel said. “There’s a lot of crying [in the locker room], but it hasn’t hit me yet. I’m going to be sad to not play with some of these seniors ever again, but now, I just can’t stop smiling.”

Last year’s NCAA title was Minnesota’s first since 2005. Frost said that team’s motto was “Prove it” because they kept having good teams fall short of the championship. This year’s motto was “Leave no doubt.”

MARLIN LEVISON &#x2022; mlevison@startribune.com

The Gophers celebrated their Frozen Four championship victory Sunday over Boston University.